Mechanical Properties and Corrosion Resistance of Hot-Pressed Dysprosium Molybdate Samples

Abstract

The purpose of this work was to study the consolidation features using hot pressing method of dysprosium molybdate billets and to study their mechanical properties and corrosion resistance.Methods. The technological and physical properties of the mechanosynthesised dysprosium molybdate powder were investigated. Properties and structure of the obtained dysprosium molybdate powder were studied by methods of chemical and X-ray phase analyses and scanning electron microscopy. Bulk density of dysprosium molybdate powder was studied according to GOST 19440-94. Flowability of dysprosium molybdate powder was determined according to GOST 20899-75. The specific surface of dysprosium molybdate was determined using a specific surface analyser NOVA 1200e (USA) by the method of low-temperature nitrogen adsorption (BET). X-ray phase analysis of mechanosynthesised dysprosium molybdate powder was carried out on a diffractometerResults. The bending strength of hot-pressed dysprosium molybdate specimens was determined, it was found that the highest value of the bending strength was recorded for these specimens at a pressing pressure of 35 MPa and is 314 MPa. The corrosion resistance of hot-pressed dysprosium molybdate samples in aqueous coolant at a temperature of 100 °C was studied. It was recorded that the mass of the mechanosynthesised dysprosium molybdate specimens remained practically unchanged throughout the corrosion resistance test in aqueous coolant.Conclusion. Tests on corrosion resistance have shown absence of change of mass of samples from dysprosium molybdate during 60 hours. The bending strength of samples from dysprosium molybdate obtained by hot pressing at pressure 35 Pa, temperature 1400 oÑ and time of holding under pressure 5 min is 314 MPa.